The field below it is probably a text box field. It was empty. There was no button for "Okay" or "Cancel" or anything. No close button in a top corner.

I then selected Apple-Q from the menu to quit. But the icon remains in my Dock with the OS X indicator to say it is running. I could force quit from the Dock this time, although a regular quit didn't work.

Maybe the problem is that I installed Minion into /Applications/Games and not /Applications?